When I open :de:WP:C (shortcut for Wikipedia:Café on german Wikipedia) on my android smartphone with the Wikipedia app, it opens a very old version from September 11th 2020 (the date can be seen at the end of that page in some users signatures).

https://de.wikipedia.org/wiki/Wikipedia:Caf%C3%A9

At the very end of the page there is also a link "Vollständige Versionsgeschichte Vor 704 Tagen bearbeitet" (translated: Complete history. Last edited 704 days ago). When I click on that link, I see a change from today (May 30th)

Wikipedia:Café is a high frequency page with a lot of edits every day, since September 2020

The mobile web version and the desktop version show the current version.

I expect to see an up to date version on android wikipedia app too